The tragic loss of actress Kelley Mack sheds light on rare brain cancer
TOI World Desk | TIMESOFINDIA.COM | Aug 06, 2025, 23:19 IST
( Image credit : TIL Creatives )
Highlight of the story: Kelley Mack, famed for her role in The Walking Dead, died at 33. She battled a rare brain cancer. Her sister confirmed the news. Mack faced her illness with bravery. Diffuse midline glioma is a rare, aggressive cancer. It affects critical brain functions. Mack shared her journey with fans. She lost use of her legs.
Kelley Mack, widely known for her portrayal of Addy in The Walking Dead, passed away on August 2 at the age of 33, following a courageous battle with a rare and aggressive form of brain cancer known as diffuse midline glioma. Surrounded by her family in her hometown of Cincinnati, Mack’s death has brought renewed attention to a devastating illness with limited treatment options and no known cure.
The news was confirmed by her sister, Kathryn, in an emotional social media tribute. She described Mack as “a bright, fervent light” who faced her illness with “bravery and grace,” leaving behind a legacy of talent, resilience, and creative spirit.
Gliomas are tumors that originate in the glial cells—supportive cells that surround neurons in the brain and spinal cord. While gliomas are among the most common types of brain tumors, the specific form that Mack battled—diffuse midline glioma—is exceptionally rare and notoriously difficult to treat. These tumors tend to develop in critical regions such as the brainstem, thalamus, and spinal cord, affecting essential functions like breathing, movement, and consciousness. Their diffuse growth pattern makes surgical removal virtually impossible.
Mack had openly shared her diagnosis with fans, revealing that the tumor had affected her spinal cord. In a January Instagram post, she disclosed that she had lost the use of her right leg and most of her left leg following a biopsy. Despite these physical challenges, she remained hopeful and documented her rehabilitation journey, often posting updates on her mobility and recovery with the support of her partner.
Diffuse midline glioma is considered one of the most aggressive and lethal forms of cancer. It resists both chemotherapy and radiation, progresses rapidly, and is most often diagnosed in children. Mack’s case as a young adult illustrates the unpredictable nature of this illness. Experts continue to search for answers, but the exact causes of the disease remain largely unknown. Research into targeted therapies and genetic mutations is ongoing, yet a breakthrough remains elusive.
Kelley Mack, born Kelley Lynne Klebenow on July 10, 1992, began her career in commercials before transitioning to television and film. In addition to her role in The Walking Dead, she appeared in hit shows such as Chicago Med and 9-1-1. She also lent her voice to Gwen Stacy in Spider-Man: Into the Spider-Verse and starred in independent films including Broadcast Signal Intrusion and Mr. Manhattan.
Beyond acting, Mack was a passionate filmmaker. She wrote, directed, and edited several short films, including Positive, and served as executive producer for the upcoming feature Universal. Her commitment to storytelling and artistic expression extended far beyond the screen, showcasing a creative drive that touched audiences and collaborators alike.
Mack’s passing has left a deep void in the entertainment industry and among fans, but it has also raised critical awareness of a rare and devastating disease. Her bravery in facing a terminal diagnosis and her openness in sharing her experience continue to inspire, even in her absence.
The news was confirmed by her sister, Kathryn, in an emotional social media tribute. She described Mack as “a bright, fervent light” who faced her illness with “bravery and grace,” leaving behind a legacy of talent, resilience, and creative spirit.
Gliomas are tumors that originate in the glial cells—supportive cells that surround neurons in the brain and spinal cord. While gliomas are among the most common types of brain tumors, the specific form that Mack battled—diffuse midline glioma—is exceptionally rare and notoriously difficult to treat. These tumors tend to develop in critical regions such as the brainstem, thalamus, and spinal cord, affecting essential functions like breathing, movement, and consciousness. Their diffuse growth pattern makes surgical removal virtually impossible.
Mack had openly shared her diagnosis with fans, revealing that the tumor had affected her spinal cord. In a January Instagram post, she disclosed that she had lost the use of her right leg and most of her left leg following a biopsy. Despite these physical challenges, she remained hopeful and documented her rehabilitation journey, often posting updates on her mobility and recovery with the support of her partner.
Diffuse midline glioma is considered one of the most aggressive and lethal forms of cancer. It resists both chemotherapy and radiation, progresses rapidly, and is most often diagnosed in children. Mack’s case as a young adult illustrates the unpredictable nature of this illness. Experts continue to search for answers, but the exact causes of the disease remain largely unknown. Research into targeted therapies and genetic mutations is ongoing, yet a breakthrough remains elusive.
Kelley Mack, born Kelley Lynne Klebenow on July 10, 1992, began her career in commercials before transitioning to television and film. In addition to her role in The Walking Dead, she appeared in hit shows such as Chicago Med and 9-1-1. She also lent her voice to Gwen Stacy in Spider-Man: Into the Spider-Verse and starred in independent films including Broadcast Signal Intrusion and Mr. Manhattan.
Beyond acting, Mack was a passionate filmmaker. She wrote, directed, and edited several short films, including Positive, and served as executive producer for the upcoming feature Universal. Her commitment to storytelling and artistic expression extended far beyond the screen, showcasing a creative drive that touched audiences and collaborators alike.
Mack’s passing has left a deep void in the entertainment industry and among fans, but it has also raised critical awareness of a rare and devastating disease. Her bravery in facing a terminal diagnosis and her openness in sharing her experience continue to inspire, even in her absence.